The 26-year-old actress reflected on the 36-year-old actor's relationship with her 52-year-old mother in an interview with Access Hollywood. Kutcher was 25 when he and Moore started dating in 2003, and Willis suggested it was overwhelming for the star to begin seeing someone with three children.
"I realized the other day that he was a year younger than me when he and my mom started going out," she remarked. "That would be like me meeting someone who already had three teenage kids. Kind of going into that situation was crazy."
"My mom has always made how [my sisters and I] feel about situations the most important thing," she shared. "I think it was more her going, 'Hey, this is my life and these are my kids and my priorities. So if you want to come and kind of join our crazy claim, this is what I already have kind of built.'"
"I find [that] so amazing and respectful," she opined. "It's one of the things that I admire most about my parents, is that they set such an incredible example for kind of putting their children first and keeping a family together, no matter what."
Willis is the eldest daughter of Moore and actor Bruce Willis. The former couple were married from 1987 to 2000, and have two other daughters, Scout and Tallulah. Moore and Kutcher married in 2005, and finalized their divorce in 2013.
Kutcher got engaged to Mila Kunis in February, and the couple welcomed their first child, daughter Wyatt Isabelle, in September. Willis reached out to her former stepfather after Wyatt was born, and said the baby is "very cute."